Jonah Lehrer looks at various creative peaks:
While physics, math and poetry are dominated by brash youth, many other fields are more amenable to middle age. (Simonton's list includes domains such as "novel writing, history, philosophy, medicine".) He argues that these fields show a very different creative curve, with a "a leisurely rise giving way a comparatively late peak, in the late 40s or even 50s chronologically, with a minimal if not largely absent drop-off afterward."
(These differences are also cross-cultural: for instance, the age gap between the creative peaks for poets and novelists has been found in every major literary tradition across the world, with novelists getting wise and poets getting stale.) This suggests that the most efficient allocation of grants in these fields - at least if we want to fund innovation - is to fund medical researchers, philosophers and novelists in middle age, when they're tenured and deeply "encultured". Sometimes, innovation requires decades of education. That might not be romantic - it's amazing how many cliches of creativity come from 19th century British poets - but it's the demographic reality.